Doctored clip linked to firm close to Thaksin family

Yingluck is known as an active supporter of the Pheu Thai Party.

The doctored clip was sent from the company to the Pheu Thai's public relations and information technology office before the distribution to about 30 reporters on the party beat and the circulation on the Internet, Buranaj said.

The clip, in circulation since Tuesday, was designed to smear Prime Minister Abhisit Vejjajiva, he said.

The timing of the clip release appeared to have an ulterior motive to rouse the crowds ahead of the Sunday's rally by the red shirts, he said.

Abhisit Friday confronted a Pheu Thai Party MP Somchai Phetpraset over the audio clip.

Abhisit caught Somchai off of guard when he asked the MP from whom he had received the clip.

Somchai met the prime minister to submit a letter to complain about alleged corruption in a purchase project of the Army.

"It's good to meet you here. Some said the audio clip came from you. Where did you get it?" Abhisit asked.

Somchai appeared stunned and scrambled to deny any knowledge about it: "It wasn't me. I knew nothing.

"Really! You knew nothing, really" Abhisit asked back.